3 key metrics to watch if Meta's AI spending is paying off

Meta Platforms plans to spend $135 billion to $145 billion on AI capital expenditures in 2026, with operating margins halved to 20% and negative free cash flow of $2.1 billion in Q3, prompting investor scrutiny of the strategy's returns. Advertising revenue rose 25.9% year over year last quarter, supported by 10% growth in impressions and 14% in pricing, though the AI-specific contribution is unclear. New products like the Muse AI agent, with 10 million users in the U.S. and Canada, and the Meta Enterprise Platform are being watched for monetization potential. Operating cash flow grew 21.7% through the first nine months of 2026, but lagged the 72% increase in capital expenditures. The company plans to raise nearly $100 billion in equity capital to fund the AI build-out, with a return to positive free cash flow potentially far off.